Technical Data
MDA5 (Melanoma Differentiation-associated Protein 5, MDA-5, Interferon-induced Helicase C Domain-containing Protein 1, Clinically Amyopathic Dermatomyositis Autoantigen 140kD, CADM-140 Autoantigen, Helicase with 2 CARD Domains, Helicard, Hlcd, IDDM19, Int
Antiviral innate immunity depends on the combination of parallel pathways triggered by virus detecting proteins in the Toll-like receptor (TLR) family and RNA helicases, such as Rig-I (retinoic acid-inducible gene I) and MDA-5 (melanoma differentiation-associated antigen 5), which promote the transcription of type I interferons (IFN) and antiviral enzymes (1-3). TLRs and helicase proteins contain sites that recognize the molecular patterns of different virus types, including DNA, single-stranded (ssRNA), double-stranded (dsRNA), and glycoproteins. These
antiviral proteins are found in different cell compartments, with TLR proteins (i.e. TLR3, TLR7, TLR8 and TLR9) found on endosomal membranes and helicases localized to the cytoplasm.
Rig-I expression is induced by retinoic acid, LPS,IFN, and viral infection (4,5). Both Rig-I and MDA-5 share a DExD/H-box helicase domain that detects viral dsRNA and two amino-terminal caspase recruitment domains (CARD) that are required for triggering downstream signaling (4-7). Rig-I binds both dsRNA and viral ssRNA that contains a 5’-triphosphate end not seen in host RNA (8,9). Though structurally related, Rig-I and MDA-5 detect a distinct set of
viruses (10,11). The CARD domain of the helicases, which is sufficient to generate signaling and IFN production, is recruited to the CARD domain of the MAVS/VISA/Cardif/IPS-1 mitochondrial protein, which triggers activation of NF-kB, TBK-1/IKK-e, and IRF-3/IRF-7 (12-15). MDA-5 (16,17), also named Ifih1 (interferon induced with helicase C domain 1), RH116 (RNA helicase-DEAD box protein 116) (18), or Helicard (19) is found to be induced by interferon. During apoptosis, MDA-5 is cleaved by caspases, separating the helicase and CARD domains (19). MDA-5 is uniquely activated by picornavirus (20) and measles virus (21).

Suitable for use in Western Blot and Immunoprecipitation. Other applications not tested.

Recommended Dilution:
Western Blot: 1:1000 Incubate membrane with diluted antibody in 5% BSA, 1X TBS, 0.1% Tween-20 at 4°C with gentle shaking, overnight.
Immunoprecipitation: 1:100
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
100ul-20°CBlue IceHumanRabbit
Not determined
Synthetic peptide corresponding to residues surrounding Arg470 of human MDA-5.
Supplied as a liquid in 10mM sodium HEPES, pH 7.5, 150mM sodium chloride, 100ug/ml BSA, less than 0.02% sodium azide, 50% glycerol.
endogenous levels of total MDA-5. Species Crossreactivity: mouse.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
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